Boron tribromide → Chrysanthemic Acid

Participants

Reaction Steps

To a solution of (+)-cis chrysanthemic acid (2.0 g) in toluene (18 ml) was added a solution of boron tribromide (13 mg) in toluene (2.2 ml) at room temperature under a nitrogen atmosphere. Irradiation with a high pressure mercury lamp (100 W) was made for 10 minutes under stirring. After the reaction was over, similar after-treatment as in Example 1 was applied to obtain chrysanthemic acid (1.98 g). The optical isomer ratio of the product was (+)-cis, 3.5%; (-)-cis, 3.2%; (+)-trans, 46.5%; and (-)-trans, 46.8%.

Provenance & Evidence